I am a native speaker who is learning about how Chinese grammar works. I know that a simple sentence contains a subject (主语), a verb (谓语?) and an object (宾语).
I am also aware that there are other "X语" like 状语, 表语, 补语 etc. I have little to no understanding of how they come into play.
I came across this sentence:
Obviously, 我 is the subject, 去 is the verb. But which is the object? 北京 or 旅行? If either of them is the object, then what is the other one? 补语?